JP2005508747A5 - - Google Patents

Description

Sieving sieve

This invention relates to sieves such as those suitable for vibrating sieve machines, often known as shale shakers, used to separate solids from fluids. An area where such machines are particularly applicable is the oilfield drilling industry, which separates drilling mud from the base fluid after it has been collected from holes drilled during drilling.

BACKGROUND OF THE INVENTION US Pat. No. 5,944,197 is a woven wire mesh that intersects a plurality of parallel longitudinal filaments with a plurality of parallel transverse filaments, A net is disclosed that has a number of longitudinal filaments per area that is greater than the number of transverse filaments, thereby forming a rectangular opening when woven. According to this, each opening has a certain length and width dimension, and a mesh with such a rectangular opening has some desirable properties for certain types of mud filtration. I know that

  According to U.S. Pat. No. 5,944,197, the ratio of the length and width of each rectangular opening is optimal within the range of 2.7 to 2.8, and the length of each opening and the transverse filament It has been found that the ratio to the diameter is optimal within the range of 5.5 to 5.7. The U.S. patent further teaches that in order to take advantage of the rectangular openings in the mesh, the gap structure must be fixed to prevent vertical and horizontal wires from sliding during operation. Thus, by calendering the screen between a pair of rollers, the filaments are compressed at the intersection of the vertical and horizontal wires, thereby helping to prevent the movement of the vertical and horizontal filaments. By combining the optimal wire diameter ratio and calendering, it is possible to increase the ratio of length to width employed in the net.

Ideally, the conductivity in the sieve is optimized, and this is generally true when the wire diameters of the longitudinal and lateral filaments are made as small as practical. However, desiring to increase the conductivity can adversely affect the quality of the sieve and its effectiveness. As a result of using the vertical and horizontal filaments with smaller diameters, the vertical and horizontal wires may not be vertical. In addition, reducing the wire diameter may reduce the useful life of the sieve. This is because a small diameter wire is easily worn, torn or torn. Although the mesh obtained by the teaching of US Pat. No. 5,944,197 has been found to increase conductivity and improve life when making similar sieves, compared to prior art meshes, This is because a tradeoff is made by adopting a slightly larger diameter wire while eliminating some of the transverse wires and creating a rectangular opening in the mesh, where the reduction in conductivity is Offset by increased sieving life compared to prior art mesh configurations.

  Proper calendering of the mesh helps maintain the orthogonality of the longitudinal and transverse filaments and maintains a high ratio of length to width in each of the rectangular openings when woven. However, when the calendering pressure is insufficient, the vertical and horizontal wires cannot be fixed, and the orthogonality is lost and the desired opening ratio is changed. On the other hand, if the calendering pressure is too high, the wire will be deformed excessively, resulting in a short useful life. Therefore, the production of the nets described in US Pat. No. 5,944,197 must be carried out under tight tolerances and strict control. Even if the screen is properly calendered, the vertical and horizontal filaments are deformed. As a result, if there are other conditions that shorten the sieving life, there is a possibility that failure will occur earlier than usual.

  The present invention is a woven screen mesh screen, in which the openings between the vertical and horizontal filaments are rectangular, and by maintaining the ratio of length to width, while maintaining the conduction characteristics of such a mesh, Thus, it is intended to provide a sieve that does not require calendaring of the net.

  Since the present invention relates to the use of a woven net (but not calendared) woven according to the technique described in US Pat. No. 5,944,197, such a net is of the type described therein. Refer to the same as the net. However, such a reference to a net is for a net that is manufactured without weaving the net and then performing a calendering process, and the vertical and horizontal wire materials, sizes, and openings in the net. It should be understood that this is a reference to the selection of the ratio of length to width and the ratio of opening length to transverse filament diameter.

SUMMARY OF THE INVENTION According to the present invention, a sieve is provided for use in a vibrator that separates particulate material from liquid material. The sieve is provided with a rigid rectangular support frame, which is provided with flanges along all four edges to which a sieve mesh of the type described is joined, said sieve being further tensioned in the frame. Underneath the mesh that is passed and tensioned and joined to the frame is an array of orthogonal rigid gap structures that define a plurality of similarly sized rectangular openings, the mesh also being By being joined to the end of the stretched gap structure, the tension in the wire is maintained, and the ratio of the length and width of the openings in the mesh defined by the vertical and horizontal wires of the screen is maintained.

  Two (or more) such meshes of the type described are stretched over the frame and joined to the boundary flange and the interstitial structure in the frame, thus sieving two (or more) mesh screens. It is possible to form.

The mesh size for one of these meshes is sometimes different from the mesh size of the other meshes, and typically a coarser mesh of mesh is first placed on the frame before the coarse mesh of this mesh. A mesh with a smaller mesh size is placed on top of it, and then the two meshes are joined to the frame flange and gap structure.

  In manufacturing, one net is first placed and fixed, and then an additional net is placed and joined.

  However, alternatively and more preferably, two or more nets to be joined to the frame are simultaneously placed on the frame, where the coarser mesh net is placed under the finer mesh net, and then the net By pulling and pulling under tension, there is at least a different tension in the mesh due to the different diameters of the wires forming the mesh, and heat and pressure are applied while the tension is maintained in the mesh. In addition, the mesh is joined to the edge flanges of the frame and the gap structure in the frame, and the pulling force that generates tension is removed only after the joining process is finished, thus the tension stays in the vertical and horizontal wires of the mesh, The ratio of the length and width of the openings in the mesh of the mesh is maintained by joining the mesh to the gap structure and flange of the frame.

  Accordingly, the present invention also provides a method of making a sieve for use in a vibrator that separates particulate material from liquid material. This method comprises the step of placing a sieve mesh of the type described on a rigid rectangular support frame, the support frame being provided with flanges over all four edges, further defined by these four flanges. An array of orthogonal rigid gap structures defining a plurality of similarly sized rectangular openings in the area where the longer dimension for the rectangular openings in the mesh is a rectangular frame. Placing the mesh so that it is parallel to the longer length of the wire, applying tension to the mesh in both longitudinal and lateral directions, and joining the tensioned mesh to the flange to secure the mesh to the frame A process of maintaining the tension in the area of the mesh bounded by the four flanges even after the force causing the tension on the mesh is removed, and joining the mesh to the gap structure to form a mesh between the gap structures. By maintaining the aspect of the relative position of the wire, and a step of maintaining a ratio of length to width of the opening in the network defined by the interwoven horizontal and vertical wires.

  The tension applied to the mesh in contact with the frame is preferably different from the tension in the mesh above it. Similarly, the mesh size of the lower mesh can be made coarser than the mesh size of the upper mesh.

  When joining with a thermoplastic material, the plastic material is heated at least at the edge or surface area of the frame portion where the mesh is to be joined, and then the plastic material is cooled to place the mesh in place. Will hold on.

  The type of mesh described is secured to an edge flange and a metal framework that defines an orthogonal gap structure, which is covered with a suitable plastic material that, when heated, accepts the mesh and causes the mesh to cool when cooled. Although particularly applicable to the present invention is in so-called composite frames, which can be joined to a framework, at least four outer members and gap structures are formed from an array of metal wires and / or metal bars This is encapsulated in a plastic material, preferably a glass reinforced resin material, such as the resin materials described in British Patent Nos. 2322590 and 2337019.

Accordingly, the present invention provides a sieve for use in a vibrator that separates particulate material from liquid material. The sieve comprises a rigid rectangular support frame which is provided with flanges along all four edges to which the sieve mesh of the type described is joined, and is defined by the longitudinal and transverse wires of the mesh. The longer dimension for the first aperture is parallel to the longer dimension for the frame, and the frame includes orthogonal rigid gaps that define a plurality of similarly sized rectangular openings or windows within the four flanges. Including an array of structures and joining the mesh to the gap structure for the purpose of maintaining the ratio of the length and width of the openings in the mesh defined by the longitudinal and transverse wires, the longitudinal and transverse wires of the mesh are tensioned And then joined to the flange and gap structure.

  Preferably, before joining the coarse mesh first net to the frame, two additional woven nets are placed on this net, and all the nets are individually tensioned before a single net. Joined to the flange and gap structure under pressure in the process, the mesh size of the two further meshes is smaller than the mesh size of the first mesh and slightly different between one and the other of the two further meshes.

  By applying tension across the frame to the type of net described and joining at the periphery, as well as along each line of the interstitial structure with a matrix of struts defining a number of rectangular openings in the frame It was found that even if the calendering process was omitted, the orthogonal integrity of the vertical and horizontal wires was not impaired. The advantages associated with this are that since there is no calendering, the mesh gap structure is less likely to be deformed and weakened, the life of the sieve mesh is greatly increased, and the production of the mesh is simplified.

  Eliminating the calendering process not only eliminates the process steps that require considerable control in the manufacture of the sieve, but also eliminates the associated costs and delays. Thus, the resulting sieve has not only the advantage of manufacturing economy, but also has the advantage of extending the life of the mesh mesh that is stretched over it, if it is carried out properly in calendering. However, because the action is strong, the knuckle of the net is not exposed to a process that may weaken the vertical and horizontal filaments.

  This invention represents a surprising advance from the invention claimed in US Pat. No. 5,944,197, which the applicant has discovered that, according to the embodiments described herein, of the kind described This is because when the net is joined to the frame, the orthogonal integrity of the vertical and horizontal wires in the net is not lost even if the calendering process is omitted.

  Specifically, an internal steel reinforcement as described and claimed in each of the above British patent specifications using a mesh that is otherwise woven in accordance with US Pat. No. 5,944,197 but is not calendered. Applicants have found that by joining the net to a JRP frame containing the material, the gap structure of the net is fixed in the same way as when the net is calendered. The resulting sieve is in accordance with US Pat. No. 5,944,197, while having the light weight, high strength and rigidity characteristics of the sieves associated with the frame configurations described in each of the aforementioned British patent specifications. It has an improved conductivity associated with woven nets and has a longer sieving life compared to sieves employing calendered nets.

  The invention will now be described by way of example with reference to the accompanying drawings.

  FIGS. 1 and 2 correspond to FIGS. 2 and 6 of US Pat. No. 5,944,197, and FIG. 1 illustrates an enlarged view of a portion of a piece of perforation. The resulting sieve includes a plurality of parallel longitudinal wires such as 12 ', 14', 16 'and 18', against which a plurality of parallel transverse wires such as 22 ', 24', 26 'and 28' are provided. Cross-woven at the intersection. The longitudinal and transverse wires forming the rectangular opening shown in FIG. 1 are woven in an unstrained net as described in US Pat. No. 5,944,197, and after US Pat. It is maintained by calendering the screen before being secured to the support as described elsewhere in 197.

  As shown here, per unit area or given area, the number of vertical wires 12 ', 14', 16 ', 18' is greater than the number of horizontal wires 22 ', 24', 26 ', 28'. . The woven longitudinal and lateral wires form a plurality of intersections, and these intersections form rectangular openings such as openings 32 ', 34', 36 '. These rectangular openings have a length dimension L and a width dimension W.

  By adopting the rectangular openings 32 ', 34', and 36 ', an opening area larger than that of the square opening can be obtained. At the same time, the sieving vertical wires 12 ', 14', 16 ', 18' effectively block or screen solid particles of larger diameter than the space between them.

  The length L of the rectangular opening to the width W of the rectangular opening can be expressed as a ratio. It has been found that the optimum length to width ratio for each opening is approximately 2.7 to 2.8.

  According to US Pat. No. 5,944,197, a method of making a sieve includes calendering the top or top sieve screen between a set of rollers. In the calendering of the sieve mesh, the mesh is compressed at the vertical and horizontal intersections. This works to suppress the movement between the vertical and horizontal wires and to help fix the crossing portion of the vertical and horizontal wires in place.

  FIG. 2 shows a top view of the sieving net 74 ′ after the calendering. Intersections or knuckles, such as 76 'and 78', are flattened by rollers. In addition, although not visible, the wires are recessed or slightly deformed according to each other where the vertical and horizontal wires cross and touch each other.

  It has also been shown that the length of each opening relative to the diameter of the transverse wire can also be expressed as a ratio. The optimum ratio of the length of each opening to the diameter of the wire is a ratio of approximately 5.5 to 5.7.

  Specifically, as shown in FIG. 2, the wires are flattened by the calendaring process, and the wires are weakened by the dents on the crossing surfaces where they cross each other at the intersection. The present invention avoids this.

FIG. 1 illustrates the relationship between the length L of the opening and the diameter d of the transverse wire. This relationship can be expressed as follows:

L / d = 5.5-5.7
Here, “L” is the length of the opening, and “d” is the diameter of the transverse wire. The length “L” of the opening is an actual opening, and is not the distance between the center of one horizontal wire and the center of the adjacent horizontal wire.

The following figures of the drawings illustrate a method for producing a filter sieve according to the present invention and an apparatus for producing such a sieve. This filter sieve can be used as a filter in a vibration filtering device such as a shaker. Shakers are used in oil field drilling to separate solids from the liquid phase of oil and water-based mud collected from drilling operations. Such a sieve is described in patent specification number WO 95/23655. This sieve has upper and lower mesh nets with different characteristics, which are stretched over a metal rod reinforced frame made of plastic material, and the nets are tensioned against them and then bonded with an adhesive. The More recent patent specification number WO 98/37988 discloses a frame to which a tensioned net can be joined, and for this joining, the surface of the frame is heat softened and then softened plastic material. The corresponding part of the net is pressed against, and finally the plastic material is cooled and cured.

  The method and apparatus described herein allow for a method of manufacturing a filter screen, in accordance with which a frame made of plastic-coated metal or reinforced plastic material is positioned in a jig and at least one screen is placed on the frame. Place it on top and grip the edge with a pneumatically operated clamp supported by a jig, pneumatically drive the clamp outward from the frame to tension the mesh in the orthogonal direction and heat the tensioned mesh Join the net to the frame by pressing against the frame with the platen, release the clamp after the joining process is finished, remove the frame from the jig, and trim to the edge of the frame against the net if necessary .

  The device comprises a jig for positioning at least one frame as described above, made of a plastic-coated metal or reinforced plastic material, and a metal supported by the jig and placed on the at least one frame. An air-operated clamp for gripping the edge of the thatched net, and an air-driven tension generating means provided on the jig for driving the clamp outward from the frame and applying tension in the direction orthogonal to the net; A platen, means for heating the platen, and means for driving the heating platen and / or jig, thereby pressing the net against the frame to locally melt the plastic material; The net is framed by embedding the net therein and then retracting the platen and / or jig to cool the at least one frame and net. After bonding, remove the frame from the jig and releasing the clamp.

  Two or three layers of mesh screen can be joined to the frame.

  Typically, the coarser mesh below the mesh is located under at least one finer mesh, and preferably two finer meshes of slightly different mesh sizes are the mesh of the coarser mesh. All three are bonded to the frame.

  Typically, the plastic material of the frame is polypropylene.

  The frame itself has a rectangular perimeter and a grid of bars that intersect perpendicularly. During the heating process, the plastic material that forms the upper surface of the frame is softened, and the tensioned net is pressed against the softened plastic material and embedded therein. The joining process is terminated by cooling the frame and curing the plastic material. A ridge may be provided on the top of the frame to assist the bonding process, in which case the heated platen used to press the net against the frame only needs to soften the ridge, which in turn accepts the wire mesh. To form a bond.

  It is highly desirable to protect the net from direct contact with the heated platen, and in order to do this, it is preferable to place a heat-resistant and non-sticky fiber, such as PTFE glass fiber, on the net prior to the joining process. This fiber is removed after completion of the joining process.

  When two or more screen nets are incorporated into the sieve, a separate set of air operated clamps is provided for each net. Similarly, a mechanism for tensioning the mesh is provided for clamping along at least two adjacent sides, preferably all four sides, of each mesh. In this way, the nets can be joined to the frame as a whole after being tensioned individually and differentially to the net as appropriate for the intended use of the sieve.

Each clamp includes a fixed pair of jaws that are used to grip the edge of the purse and an inflatable air bag located therebetween. A thin aluminum plate is provided to separate the air sac from the net. When inflated, the air sac presses the aluminum plate toward one of the jaws.
The aluminum plate is preferably lined with a 3 cm wide rubber (or similar material) strip, which improves the gripping of the edge of the mesh sandwiched between the aluminum plate and the jaws.

  In addition, a control panel is provided to allow the jig operator to activate the pneumatic clamp and pneumatic tension generating means. Preferably four control panels are provided, so that the operator can use one control panel to feed the mesh into the clamp along one side of the frame, activate these clamps and tighten this edge of the mesh. It is possible to move to the next frame side and repeat the above procedure for this frame side. If there are two or more levels in the clamp and tension generating mechanism, with one level for each layer of the mesh, the first mesh is tensioned by tightening individually on all four sides and then for the next mesh Work in the same way, thus tightening and tensioning all nets as appropriate.

  The first work place where the process of tightening the net and applying the tension is separated from the second work place where the joining process is carried out. Thus, in order to allow the jig to move between these work locations, aerodynamic forces for the clamp and tension generating mechanism are supplied to the jig through the flexible supply cable.

  Therefore, initially, the at least one frame is loaded into a jig supported by a gantry, and after the net is tightened and tensioned, the gantry is transported to a second work place including a heated platen.

  Preferably, the cradle has wheels that run on rails, along which the cradle is driven by a linear drive between the first and second work sites, including a festo (festo). ) A linear pneumatic drive is convenient.

  Preferably, the platen is preheated, and when it is in a fixed position, the jig base is lifted to the platen by the water hammer pump to start the joining process. Thus, it is possible that the water hammer pump acts on the lower side of the cradle and the cradle lifts it from the rail driven between the first and second work sites.

  When a non-sticky fiber is placed on a net and then engaged with a heated platen, the operation of placing the fiber on the net may be performed at the first or second work site, or during the transition. .

  Typically, the platen is preheated at a temperature in the range of 200-300 ° C, preferably about 250 ° C.

  The hydraulic pressure for the water hammer pump can be adjusted within a range of 500-2000 psi to suit the sieving material used, particularly the mesh or combination thereof.

  The period of applying hydraulic pressure to perform the squeezing, heating and joining process is typically in the range of 30 seconds to 2 minutes.

  At the end of the heating and joining process, the material is cooled and hardened across the jig base and the platen, and finally the jig base is transported again from the second work place to the tightening / tension generating work place. An operator can release the clamp, remove the protective fibers, remove the frame from the fixture rack, and trim the net that extends beyond the edge of the frame.

To increase production speed, the two frames are placed side by side so that they are covered at one time, and a large area net is stretched over both frames, one for each layer. After the joining process, this large area net is cut along a line between two side by side frames. Thus, the fixture base is relatively large, but the time it takes to fit and tighten each large sheet is necessary to handle a smaller area net on a single frame as well. It will be appreciated that, with little change in time, each heat-bonding process results in two sieves instead of just one.

  Preferably, each clamp for any one layer can move out of the frame individually and independently of each other, i.e. each clamp has a separate coupled tension generating mechanism, thus Such local slack can be eliminated.

  For each frame edge, a coarse bar may be positioned just in front of each line for the clamp, and the mesh will move over it when tensioned, thus removing the wrinkles on the mesh.

  Referring to FIGS. 3-13, the apparatus illustrated herein includes a support framework 10 that, at one end thereof, forms a jig to allow assembly of a sieving frame at an assembly work site 14. The gantry 12 is supported, and at the other end, it is integrated with a heating platen support unit 16 constituting the joining work place 18. The gantry 12 has wheels running on rails 22, 22 </ b> A separated in parallel, and thus the gantry can be moved between two work sites by a drive device 23 (see FIG. 10). At least one rail and the corresponding wheel are designed to ensure that the cradle moves in a linear path.

  The drive includes a pin 25 that engages a groove 27 in the plate 29, the latter of which is secured to and extends from the cradle (see FIG. 10). The drive device 23 is a Fest (registered trademark) linear pneumatic drive device.

  A flexible supply umbilical cord 24 transmits electrical and pneumatic energy to the cradle.

  In the sieve assembly work place, two GRP sieve support frames 26 (only one is shown in FIG. 3) are arranged side by side in the jig frame 12. FIG. 4 shows one of the frames 26 located within the gantry 12, with the space for the second frame 26 on its side. The plan view of the device (FIG. 12) also shows one frame positioned within the jig. Each frame 26 includes bars of glass fiber reinforced polypropylene described in the patent specifications WO 95/23655 and WO 98/37988, forming a straight grid, intersecting perpendicularly and reinforced with wire. As is well known, the peripheral edge of the frame and the top surface of the cross bar are shaped with upstanding ridges.

  After the two frames are positioned in the jig, the woven filter net is placed on the frame in sequence, and the edge of each net is inserted into the pneumatic clamp unit 28 supported by the jig. This grips and then places the next net. The pneumatic clamp unit is shown in more detail in FIG. The vertical and horizontal wires of the mesh define a rectangular opening, and when placing the mesh on the frame, the longer dimension for the rectangular opening in the mesh is the longer edge for each frame. And parallel.

Each clamp includes a fixed upper jaw 28A and lower jaw 28B, of which the lower jaw supports an inflatable air sac 28C on its upward facing surface, on which a protective aluminum plate 28D is provided. The edge of the mesh is inserted between the aluminum plate 28D and the rubber strip 28E on the lower surface of the upper jaw, thus inflating the air sac 28C and tightening the mesh between the aluminum plate 28D and the upper jaw, where The rubber strip 28E reduces the risk of slippage that occurs when tensioning the net. In use, the edge of the perforated net is pulled over the coarse bar 31 and inserted between the jaws 28A, 28B between the rubber strip and the aluminum plate. The air sac is then inflated to grip the net between the rubber strip and the aluminum plate, which is done at a pressure sufficient to resist the subsequent tension applied to the net.

As best shown in FIGS. 14 and 14A , the rear edge of each aluminum plate 28D is directed upward and engages a groove on the lower side of the upper jaw 28A near the rear edge. Form.

In order to allow the net to be tensioned, the jaws 28A, 28B are joined together at the rear to form a single assembly, which is supported by the piston 28F of the double acting pneumatic cylinder 28G. The double acting pneumatic cylinder 28G and the piston 28F constitute the tension generating means, and one such means is provided for each clamp unit. When air is supplied to the front end of the cylinder 28, the piston and the jaw assembly are moved rearward away from the jig, and the gripped net is moved around the jig by the roughing bar 32 (see FIG. 6) . It stretches over the top. When air is supplied to the rear end of the cylinder, the jaw assembly moves forward to a rest position near the jig shown in FIG. 13A. This is accomplished after the mesh has been joined to the frame and the jaws have been released, as will be explained later. The coarse hitting bar 32 is for preventing local wrinkles from approaching the net while tension is applied.

  In practice, it will be understood that all four edges of the net are gripped and then tensioned, as will become apparent from the following description.

For aerodynamic system supply for the clamp units is described with reference to FIGS. 1-4 and Figure 14 A after.

  Three layers of clamp units 28 are provided so that a maximum of three nets can be stacked and fixed to the frame.

A three-layer clamp unit 28 (for example, those shown in FIGS. 6 , 13A, and 13B) is provided on all four sides of the mount, and a main control panel 30 (see FIGS. 6 and 12 ) is provided at one corner. The subordinate control panels 30A, 30B, 30C are positioned at the other corners, so that an operator can individually control the clamp and tension generating means along successive sides of the cradle from one side around Just move to the side.

  After gripping all four edges of the mesh net with the jaw of the clamp unit, pneumatically drive the jaw of the clamp unit outward from the jig using the cylinder / piston means described above, Apply tension. Each tension generating means is constituted by the above-mentioned double action pneumatic cylinder and piston, and operates independently to stretch the net on the coarse hitting bar 32 extending along the four end edges of the jig mount. This ensures that the net is uniformly tensioned without wrinkles or wrinkles.

  This process is repeated for each network. Position the first mesh with a coarse mesh between the jaws of the bottom line of the clamp 28, the finer mesh with the next line of the clamp, and another fine mesh with the third line of the clamp. Position. The mesh sizes of these two fine mesh nets are similar but not the same.

Next, as best shown in FIGS. 9 and 12, the entire cradle can be moved under the heated platen on the unit 16 to the joining work site. However, before joining, in order to prevent direct contact between the upper sieving net and the heating platen, first, a heat-resistant and non-sticky fiber, such as PTFE glass fiber, is placed on the tensioned net in the jig rack. If desired, the edge can be gripped by the clamp unit line. The jig 12 shown in FIG. 5 includes two frames 26 positioned therein, an upper mesh net 26A and a lower mesh net 26B stretched on the frame, which are partially cut away. With dissociated fibers 26C placed on these nets, shown partially cut away.

  In the joining work place, the jig is moved up and down by the platform 31 on which the water hammer pump 34 operates. The platform 31 engages with the lower side surface of the jig 12 and lifts it, thus lifting the wheels 33 and 35 from the rails 22 and 22A. When the screen over the screen is lifted, it contacts the platen 36, which is preheated by some electrical heating element (not shown).

The heated platen softens the side flanges of the plastic frame and the ridges on the upper edge of the gap structure and presses the wire across the tensioned net against the softened material. Providing ridges in the side flanges and gap structure aids the joining process described in each of the above published international patent specifications WO 98/37988 .

  After joining, the sieve assembly is moved downward and returned to the assembly work place.

Return to the assembly work site, peel off the PTFE dissociation fibers, release the tension on the mesh, cut the sieve mesh between two frames, remove each frame from the jig, and sharpen the protruding edge of the screen mesh Trim to the edge of the frame using an angle grinder. Thus, the manufacture of the sieve is completed, and the jig can receive the next two frames and the net layer for producing the next two sieves at any time. Joining the mesh to the edge and gap structure of each frame helps to maintain the shape and length to width ratio of the vertical and horizontal wires that define the openings in the mesh.

Further, FIGS. 1-4 and Figure 14 A shows the air supply line to the clamping unit. Air for inflating the air sac 28C in the jaws 28A, 28B is supplied from an air line 40. In order to completely open the space between the jaws before insertion of the edge of a new mesh net, complete exhaust of the air sac is essential. This is accomplished by applying a vacuum to line 40.

  Air for operating the dual action cylinder 28G is supplied from the air lines 42,44. When air is supplied from the line 42, the piston 28F and the clamp are driven outward from the jig according to the piston 28F, and tension is applied to the mesh net tightened between the jaws. At the end of the series of operations, when air is supplied from line 44, the clamp is driven back to the fixture, so that the clamp is again in the position shown in FIG. 13A, ie the next to join the next pair of frames. Comes in a position where you can receive the sieving net at any time.

  The aerodynamic system control system of the clamp and tension generating means is shown in FIG.

The pressurized air is supplied to a pressure regulating valve 48 and a pressure meter 48A connected thereto through an on / off valve 46, and further supplied to a pressure line 50 through a filter / valve unit 49. Air can be supplied via the aerodynamic switching circuit 52 to operate the clamp and tension generating means. The switching circuit is controlled by buttons on a control panel at the corner of the jig, and these buttons are labeled L3, L2, L1, and P1 in the drawing, respectively. Each line pressure for the clamp and tension generating means can be adjusted using a pressure regulator and a meter 54 connected thereto. The typical line pressure P1 for operating the clamp is 5.5 bar, and the typical tension generating pressure is 4.8 bar (L3) at the bottom layer of the tension generating means and 3.0 at the middle layer. Bar (L2) and 2.0 at the bottom
Bar (L1). Of course, there may be only one or two mesh screens to be loaded in the manufacture of a particular sieve, in which case some of the buttons for unused layers in the tension generating means are Do not operate. The line pressure examples given for the tension generating means are given assuming that all three layers of tension generating means are used. All the valves employed in the aerodynamic control system are solenoid valves.

  16 and 17 show the configuration of the aerodynamic system for the clamp unit. First, it should be understood that the frame joining the mesh net is a rectangle having two short sides A and B and two long sides C and D. The two frames are positioned in the jig so that their short sides A and B are in a straight line, so for the nets placed on both frames, six along each of the aligned edges Clamp units (12 in total) are required. Four clamp units (a total of eight) are provided at opposite ends of the jig along each long side of the frame.

  FIG. 16 shows a configuration of six clamp units along one side of the jig. This configuration is repeated for the other side.

  FIG. 17 shows the configuration of four clamp units along the longer end of the jig. The configuration of FIG. 17 is repeated at the other end. The configurations shown in both of these figures are for all three layers of clamp units.

In both FIG. 16 and FIG. 17, the switching valve 56 is for controlling the operation of inflating and collapsing the air sac in the clamp via the lines 58 and 60. Ventilation into the atmosphere from the air sac via line 60 releases the net and allows its edge to be removed. When a vacuum is applied to line 60 using line 62, the air sac collapses, making it easier to insert a new mesh into the clamp jaw. The valve unit 64 controls the supply of air to the pneumatic cylinder tension generating means through the lines 65 and 66 , and uses the line 65 when applying tension and the line 66 when eliminating tension.

  In FIG. 18, reference numeral 68 indicates a fuse power input terminal, and reference numeral 69 indicates a power supply to the motor for driving the oil pump. The oil pump is for supplying hydraulic oil under pressure to a water hammer pump that moves the gantry up and down at the joining work site. Reference numeral 70 indicates a power supply to the photoelectric safety circuit. The circuit stops or reverses the hydraulic drive if the light beam in the cradle path across the entrance to the joining work site is interrupted for any reason while the cradle is lifted towards the heated platen Provided for. Reference numeral 71 denotes a power supply that allows computer control of a sequence of operating procedures of the apparatus. Reference numeral 72 indicates the power supply for all AC solenoid valves employed in the aerodynamic system. Reference numeral 74 indicates the power supply for all DC solenoid valves, and reference numeral 76 indicates the power supply to the heater used to heat the platen at the joining site.

  Finally, FIGS. 19 and 19A respectively show a main control panel 30 at one corner of the jig and a secondary (or subordinate) control panel 30A, 30B, at one of the other corners of the jig. One of 30C is shown. Buttons are indicated by their function.

  Each of the main panel 30 and the secondary panels 30A, 30B, 30C, respectively, along the first, second, third and fourth sides of the jig, respectively, for all three layers of the mesh, if appropriate, Allows tightening, unfastening, and evacuating the clamp bladder.

Furthermore, the main control panel 30 makes it possible to apply and remove tension along all four sides of the jig, and these four sides include a first side from which an operator starts loading the jig. It is. Therefore, the operator first positions the edge of the mesh in the clamp along the first side of the jig, and then operates the clamp using the main control panel 30 to tighten the edge, and then the jig. The edge of the net is tightened in order of the second, third and fourth sides. The operator then returns to the main control panel, where he presses the appropriate tension generating button to activate all pneumatic cylinder tension generating means simultaneously and moves all clamps for a layer outward simultaneously, thus The net associated with this layer can be tensioned.

  When loading is complete and the cradle returns to the assembly site, the operator can first use the main control panel 30 to apply pressure to reverse all tension generating pneumatic cylinders in all mesh layers. it can.

  Any tightening can be released by evacuating all inflated air sacs into the atmosphere, and applying a vacuum to all air sacs can help level the air sacs and help insert the edges of the next purse. it can.

  While applying tension, the same air pressure is applied to the piston of the pneumatic tension generating means, and the pneumatic tension generating means do not move exactly the same, but each is predetermined and set in all parts of the net. It may move as much as necessary to apply tension to the desired extent.

FIG. 3 is an enlarged partial view of a mesh woven according to US Pat. No. 5,944,197 before the calendering step. It is a figure which illustrates the net | network after the process of a calendar process proposed by US Patent 5,944,197. This step is omitted when making the mesh used in the sieve proposed by the present invention. FIG. 2 is a perspective view of a wire reinforced molded GRP frame in which a woven woven net is stretched and joined to produce a sieve of the present invention. FIG. 4 is a perspective view of one corner of a jig for applying tension to a perforated net of up to three layers over a frame such as that shown in FIG. 3. FIG. 4 is a view similar to FIG. 4 in which a coarse mesh net is placed over the frame and tensioned, and then similarly, a fine mesh mesh is placed on the first tensioned net. It is a figure. Each net is of the type shown in FIG. It is an end elevation which expands and shows the clamping | tightening and tension | tensile_strength production | generation mechanism of the jig | tool of FIG. It is a front view of the jig | tool of FIG. It is a side view which shows the whole apparatus containing the mount frame which mounts a jig | tool. Here, the jig can be moved between the tension generating work place and the joining work place and removed after the sieve is completed. It is a side view which shows the whole apparatus containing the mount frame which mounts a jig | tool. It is a side view which shows the whole apparatus containing the mount frame which mounts a jig | tool. It is a side view which shows the whole apparatus containing the mount frame which mounts a jig | tool. It is a side view which shows the whole apparatus containing the mount frame which mounts a jig | tool. It is a figure which shows what is clamp | tightening and tension | tensile_strength production | generation means, and can advance and can receive the edge of a net | network at any time. FIG. 3 is a diagram showing a tightening / tension generating means fully retracted to help apply tension to a net gripped by its jaws. It is the schematic of the means for hold | gripping a net | network and applying tension | tensile_strength. It is the schematic of the means for hold | gripping a net | network and applying tension | tensile_strength. It is a schematic diagram of a control system for grasping a net and applying tension. It is a schematic diagram of a control system and means for gripping a net and applying tension. It is a schematic diagram of a control system and means for gripping a net and applying tension. It is a schematic diagram of a control system for grasping a net and applying tension. It is an enlarged view of the main control panel. It is an enlarged view of other control panels.

Claims (20)

  A method of making a sieve for use in a vibrator that separates granular material from liquid material, comprising placing a screen over a rigid rectangular support frame having flanges along all four edges The peg has a greater number of longitudinal wires than a transverse wire per given area, thus defining a plurality of rectangular openings each having a length to width ratio of approximately 2.7 to 2.8. And the ratio of length to wire diameter is approximately 5.5 to 5.7, and the method defines a plurality of similarly sized rectangular openings in the area defined by the four flanges. Providing the frame with an array of orthogonal rigid gap structures, and placing the screen so that the longer dimension for the rectangular opening in the mesh is parallel to the longer length for the rectangular frame. Applying tension to the mesh in both longitudinal and lateral directions, joining the tensioned mesh to a flange to secure the mesh to the frame, and thus within the area of the mesh bounded by the four flanges. Maintaining the tension, removing the force that generates tension in the mesh, joining the mesh to the gap structure, and positioning the vertical and horizontal wires in the mesh between the gap structures. Maintaining the ratio of the length and width of the openings in the mesh defined by the interwoven lengthwise and horizontal wires without the step of calendering the mesh. .   The method of claim 1, wherein a second mesh is placed on top of the first mentioned mesh, and the tension applied to the mesh in contact with the frame is different from the tension in the second mesh.   The method of claim 2, wherein the mesh in contact with the frame has a coarser mesh than the second mesh.   4. The method of making a sieve according to claim 2 or claim 3, wherein one mesh is first placed on and joined, and then an additional mesh is placed on and joined to the frame. Two or more nets to be joined to the frame are placed on the frame in turn and gripped and tensioned, and heat and pressure are applied while tension is maintained on the stretched net, The mesh is simultaneously joined to the edge flange of the frame and the gap structure in the frame, and the force causing the tension is removed only after the joining is finished, and thus the force is removed when the force is removed. The method for producing a sieve according to any one of claims 1 to 3, wherein tension remains in a vertical wire and a horizontal wire of the mesh.   A thermoplastic material is employed to perform the joining, which heats the plastic material at least at the edge or surface area of the frame portion where the mesh is to be joined, and then allows the plastic material to cool. The method for producing a sieve according to any one of claims 1 to 5, wherein the method is performed by mooring the net at a fixed position on the frame.   A metal frame is adopted, the metal framework is covered with a thermoplastic material abundantly before placing the net on the frame, and the thermoplastic material softens when heated and embeds the net in it, cooling 6. The method of making a sieve according to any one of claims 1 to 5, wherein the mesh is sometimes joined to the framework.   The frame is molded from plastic material and is strengthened in its entirety by an array of pre-assembled wires and / or rods, and the screen heats the surface of the molded product in contact with the net stretched over the surface of the frame The method for producing a sieve according to any one of claims 1 to 5, wherein the sieve is formed by softening a region and embedding and joining the mesh when the frame is cooled.   The mesh is woven from wires of similar metal composition and the same force is applied to different meshes, and the tension in the vertical and horizontal wires of the mesh is related to the diameter of the wire forming the mesh. Sieve produced according to the method of   5. A sieve made according to the method of claim 4 wherein the mesh is subjected to forces that produce different tensions to establish different tensions in different mesh layers.   A sieve used in a vibrator manufactured according to the method according to any one of claims 1 to 8, comprising a rigid rectangular support frame, and a net is joined to the support frame. Flanges are provided along all four edges, the longer dimension for the rectangular opening defined by the vertical and horizontal wires of the mesh being parallel to the longer dimension for the frame, Within the four flanges, includes an array of orthogonal rigid gap structures defining a plurality of similarly sized rectangular openings, the mesh having a length of openings in the mesh defined by longitudinal and transverse wires; A sieve that is joined to the gap structure for the purpose of maintaining a width ratio, wherein the longitudinal and transverse wires of the mesh are tensioned before being joined to the flange and the gap structure.   Before the first net is joined to the frame, at least one further woven net is placed on the first net and both nets are tensioned before a single net. 12. The sieve according to claim 11 joined to the flange and the gap structure under pressure in a process.   The sieve according to claim 12, wherein the first net has a tension different from that of the net that overlaps the first net.   14. A sieve according to claim 12 or claim 13, wherein there are two meshes, and the mesh of the first mesh that contacts the frame is coarser than the mesh of the mesh that overlies the mesh.   There are three meshes, the mesh of the first mesh contacting the frame is coarser than the meshes of the other two meshes on it, and the mesh of the two meshes is more than the mesh of the first mesh with a coarse mesh. 14. A sieve according to claim 12 or claim 13 which is much finer. 16. The sieve according to claim 15, wherein the mesh size for one of the two overlapping nets is substantially the same but not the same as the mesh size for the other. A sieve used in a vibrator for separating granular material from liquid material,
a) a rigid rectangular support frame with flanges along all four edges;
b) an array of orthogonal rigid gap structures mounted within the frame and defining a plurality of similarly sized rectangular openings;
c) a woven net, wherein the woven net defines a plurality of rectangular openings by having a greater number of longitudinal wires than a transverse wire per given area, each opening approximately 2.7-2 A length to width ratio of about 0.8, the ratio of the length to the diameter of the wire being approximately 5.5 to 5.7;
d) The mesh is stretched across the frame and tensioned in both longitudinal and lateral directions, and is joined to the frame on which the mesh is stretched and the edge of the gap structure;
e) Sieve thus maintaining the tension in the wire and the ratio of the length and width of the opening defined by the longitudinal and lateral wires of the mesh without calendering the mesh.   18. The at least two perforated nets, each as described above, are stretched over the frame and joined to boundary flanges and gap structures within the frame to form a multi-layer screen. Sieving.   The sieve according to claim 18, wherein the mesh size for one of the meshes is different from the mesh size for the other.   20. A sieve according to claim 19 wherein a smaller mesh size mesh overlays a coarser mesh mesh, and both meshes are tensioned and joined to the frame and gap structure.